What I do is just bounce my stick on a practice pad.  Usually when watching TV.  I try different fulcrums, moeller strokes, finger pulls.

We used to do fulcrum exercises at MI.  I have also visited the Art Verdi webpage.  His hands are blazing and work very efficiently.  You can study Gladstone, Chapin or the Dom Famularo technique.

I think Gary Chaffee's New Breed has alot of 16th note exercises also IIRC.

Just keep it slow, relax, speed up then repeat.  It takes awhile.  Try to let your drumhead, stick and fingers work in harmony- you need less wrist than you think for fast technique.  The wrist whip is for power.

You can practice with a metronome also.  Slowly increase speed by one BPM at a time.  You can keep a daily chart to log progress if you like.  It's a good idea.

Think of it as making yourself stronger.  You'll gradually lift things that are heavier and heavier as you grow accustomed to a certain weight.  Same goes for hands and speed.  Pick a speed where you can play but almost feel like you're going to give out.

I like to do 16th note triples flamming the 1 + 2 + 3 + 4 + and playing all other notes soft inbetween.

I like to do RRRR RRRR RRRR RRRR LLLL LLLL LLLL LLLL 50 or so times at all different speeds.

Sounds like the original Moeller tecnique as taught to Jim Chapin by S.A. Moeller.  Except the tip strike is secondary. What you would actually be doing on the second strike is a pull out. Kenn Aronoff uses it,he also learned it from Jim.

Here it is in a triplet pattern.Throw down the first hit,at the time of the strike you arm should be parralell to the floor, then the wrist bends down to execute the second strike as the arm raises.
The real Moeller method is to hold the stick very loose,it should move in your hand,down ,tap,up.The up is a pull out. The tap should play itself.
For four notes you would play down,tap,tap up. Remember to let the stick move in your hand.
You can see an example on the Vic Firth website,cyber lessons with Dom Famularo,Moeller for the heavy hitter I think its called.Its with Dom and Jim.

That would be the center of percussion on the drumstick, a point which, when struck, will result in the forward translational velocity and the backward rotational velocity being equal and opposite—in other words, when the drumstick is held at this point, it feels good and the drumstick seems to move with a minimum of effort.